Refrigerating system and process



Jan. 12 1926. 1,569,744

W. GREEN REFRIGERAT ING SYSTEM AND PROCESS Filed Dec. 20, 1922 1 Wvflvma M 19243.0

Patented Jan. l2, l926.

.UNITED STAT S PATENT owl-e WILLIAM GREEN, F NEWTON, MASSACHUSETTS.

nn'rnronnn'rme SYSTEM AND PROCESS.

Application filed December 20, 1922. Serial No. 608,079.

T 0 all. whom it may concern:

. able, or where, for any reason, the system Important examples of such systems arev must operate practically without attention.

household refrigerators and other small refrigerating plants.

A great many attempts have been "made heretofore to develop a satisfactory refrigerating system of the general type above men- 'tioned designed to meet these requirements.

While considerable regress has been made in this direction, sti 1 no system of which I have been able to learn has proved successful, chiefly for the reason that all such sys-.

terms have required the use of automatic valves to control the flow of the refrigerant,

and these valves after a-time get out of order and render the entire system inoperative. It is the chief object of the present inven-- tion, therefore, to improve both refflgerating processes and systems of the intermit- "tent absorption type with a view to avoid- I will be particularly pointed out in the ap- -pended claims.

ing the use of valves or equivalent devices for controlling the flow of the refrigerant.

The nature of the invention'will be readily understood from the following description I when read in c'onnection-.. with the accompanying drawings, and-the novel features In the accompanying drawings, the single figure is a diagrammatic view. of-a refrigerating system constructed in accordance with the present invention.

In the system shown, 2 designates the com bined stil and absorber, 3 the condenser, and 4 the expansion chamber. The absorber is connected with the condenser. through a pipe 5, and the end of the condensing coil 3 runs directly into the expansion. chamber 4 so that the condenser and expansion chamher are always in open'communlcation with flow of refrigerant between them' at all tunes- This system is designed to employ any of the well known refrigerants adapted each other, affording a free passage for the for use in an intermittent absorption system,

ammonia being acom'mon example of such a refrigerant. An absorbent of either solid or liquid form may be used, a solid absorbent such as ammonium nitrate being satisfactory. The expansion chamber 4 is located III-'8, brine tank 7 ,w-hich is formed in two sections, as shown, the upper section being outside the refrigerator box 8, while the lower section is located within said box. The two sections are so connectedthat a free passage for the flow of brine between .them

is afforded at all times.

The cooling water flows through-the con- 2' v tamer 9 in which the condensing coil-31s located, andthence, during the expansion cycle, through a pipe 10 into the bottom of a tank'12 and through an overflow pipe 14 condensing period this water flows from the pipe 10 thr0ugh' a valve 17 and 18 to f waste at '19.

The combined still and absorber 2 preferably contains a 'coil 20, the lower. end of to a coil 15 located in the absorber'2 and thence to the. waste pipe 16. During the which is connected with a. boiler or tank 21 filled-with some heavy, relativel non-volatile liquid, such as mineral oil. eat is supplied to this tank or boiler by a burner 22 adapted to use a liquid hydro-carbon fuel.

The upper end of the coil20 is connected to.

a reflux condensing coil24'located in the tank 18.

At the-beginning of the expansion period of the cycle of operations of the system, the expansion chambers will be partially or entirelyfilled with liquid ammonia, assuming that this is therefrigerant used in'the'system. Heat is absorbed from the brine and the ammonia will evaporateand its va 'ors:

will" flow over into the absorber 2, w ere they will be taken up by the absorbent." This "-ObVlOIlSlY results in chilling the walls of the expansion chamber 4. During this time the cooling wateris flowin through the. tank 9, pipe 10, tank 12,-p1pe 14 and coil 15, i taking up heat chiefly as it flows'through the coil 15 in the absorber.

. .When substantially all of the refrigerant has been evaporated the operations above descr bed-are reversed. That is, the burner 22 1s lighted, thus heating the oil or otherliquid in the boiler 21, with the result that the ammonia is distilled ofi andseparated from the absorbent. Before, or atabout the time that i the burner 22 is lighted, the valve 17 is turned to cause the water to flow through the tank 18 and to drain the tank 12. This cools the reflux condenser coil 24- so that any vapors of theoil or other liquid used in the boiler 21 which are not condensed in the coil 20 will be condensed in the coil 24.

As the ammonia vapors are distilled oil, they are condensed in the condenser 3 and the expansion chamber 4. It will readily be appreciated that it is very important indeed,

that the greater part of the condensation shall take place in the condenser 3 and only very little,.if any, in the expansion chamher t. It is for this reason that a valve of some type has been introduced between these elements in prior systems. As above indicated, an especially important feature of this invention consists in the elimination of this valve.

I have found that the condensation can be controlled within limits suiiicientlv narrow for all practical purposes by vary ing the relative rates of heat transfer of the condenser and expansion chamber at a given temperature differential. I effect this control through the movement of the brine into and out of contact with the expansion chamher. At the beginning of the distillation portion of the cycle as the ammonia vapors come over through the condenser, the condensation naturally will tend to be greater. in the expansion chamber than in the con-.

denser, assuming other factors to be equal, because the temperature is lower in the chamber. Assuming brine still to surround" the chamber 4, this condition would continue through the greater part of the distillation 7 period. It is well known, however, that the rate of heat transfer from a solid to a liquid is very much greater than that from a solid to a gas, the ratio, roughly, being as one hundred to one. Consequently, I propose to move the brine out of contact with the expansion chamber at the beginning of the condensing step of the process so that the heat transfer of the condenser 3 for a given temperature diiference will be about one hundred times as great as the heat transfer of the expansion chamber 4.

At the beginning of the condensing or distillation period the first condensation ma parts '3 and 4 being free and unimpeded at all times.

The above described movement of the brine may be effected in any suitable manner, but the drawing shows a very simple arrangement for performing this operation. According to this construction an air bell 26 is fixed in the bottom of the brine container 7 and is connected by means of a pipe 27 with the top of another bell 28 located in the tank 12, the'bottoms of the bells being open.

As above stated, the valve 17 is opened at the beginning of the condensing or distillation period, and the tank 12 drains. Consequently, the air is released from the bell 26 and the bell fills with brine, the upper level of the brine in the tank 7 dropping to a pointbelow the bottom of the expansion chamber 4. When the condensation period has been completed, the valve 17 is closed and the burner 22 is extinguished. The water then flows again through the tank 12. filling this tank and trapping a substantial volume of air in the bell 28. A part of the air thus trapped is forced through the pipe 27 into the bell 26 thus displacing the greater part of the brine-in the latter bell. By properly proportioning the parts 26, 27 and 28 the movement of the brine may be made such that it will submerge the expansion chamber 4 during the expansion cycle and will drop to a point below the bottom of the chamber 4: during the'condensing cycle. One or more vent holes 13 are provided in the top of the tank 12 to permit the escape of air therefrom.' The heat transfer to or from the chamber 4thus is at a maximum during the expansion period, and at a minimum during the distillation or condensing period, the rate being about one hundred times greater, for a given temperature diiferential, in one case than in the other, due to the fact that in one case the transfer is between a solid and a liquid and in the other case between a solid and a gas.

It will now be appreciated that this invention eliminates the necessity for any valve mechanism whatever to control the flow of the refrigerant.

understanding of this invention. It will be appreciated that the'invention may be embodied in many forms without departing It thus eliminates the most troublesome factor of prior systems.

from the spirit or scope thereof. and that the process herein described may be successfully practiced in agreat variety of forms of apparatus.

Having thus described my invention, what I desire to claim as new is:

1. In an intermittent absorption refrigerating system, the combination of 811 absorb- 01, a condenser, connections enabling the refrigerant to flow freely at all times between said absorber and condenser, an expansion chamber into which the condensed refrigerant flows by gravity from said condenser during the condensing period, said condenser and chamber being constantly in free communication with each other, and means for varying the rate of heat transfer of said expansion chamber at a given differential temperature at different periods-in the cycle of operations of the system.

' 3. In an intermittent absorption refrigeratiiig system, the combination of an absorber, a condenser, connections for conducting refrigerant from said absorber to said condenser and vice versa, an expansion chamber for the refrigerant connected with'said condenser and permitting a free flow of refrigerant between said condenser and chamber at all times, a container for holding a quantity of brine in'contact withsaid expansion Y chamber, and means for causing the brine to be held in contact with said expansionchamher during the expansion period and out of contact therewith during the distillation -pe-- I ating system, the combination of an absorber,

riod. a

a 4. Inan intermittent absorption refrigerating system, the combination of an absorber,

a condenser, connections for conducting re ef 'igerant from said absorber to said condenser and vice versa, an expansion chamber for the refrigerant connected with said condenser and permitting a free flow of refrigerant between said condenser and chamber at all times, and means arranged to be actnated by fluid pressure for holding said brine in-contact with said expansion chamber dur- "ing the expansion period and causing it to move out of contact with saidchamber during the distillation period. f '5. In an intermittent absorption refrigerating system, the combination of an absorber,

a condenser, connections enabling the refrigerant to flow freely at all times between said absorber and condenser, an expansion chamher into which the condensed refrigerant flows by gravity from said condenser durin the condensing period, said condenser aifi chamber being constantly in free commun cation with each other, a brine container within which said expansion chamber is located, and means for effecting a movement of the brine into contact with said expansion chamber during the expansion period and out of contact therewith during the distillaftion period.

v In an intermittent absorption refrigerating system, the combination of an absorber, a condenser, connections for conducting refrigerant from said absorber to said condenser and vice versa, an expansion chamber for the refrigerant connected with said con denser and permitting a free How of refri erant between said condenser and chamber at all times, a refrigeratorbox, a brine tank located partly within and partly-outside said box, said tank being arranged to hold the 'brine in contact with said expansion chamher, and means for causing the brine to remain in contact with said chamber during the expansion period but out of contact therewith during the distillation period.

7. In an intermittent absorption refrigerating system,the combination of an absorber, a condenser, connections for conductingrefrigerant from said absorber to said condenser and vice versa, an expansion chamber for the refrigerant connected with said condenser and permitting a free flow of refrigerant between said condenser and chamber at all times, a refrigerator box, a brine tank located partly within and partly on top of said box, said expansion chamber being located within the upper part of said tank, and means for causing said brine to remain substantially out of contact with said chamber during the distillation period and for raising it and holding it in contact with said chamher during the expansion period.

8. In an intermittent absorption refrigera condenser, connections for conducting re, frigerant from said absorber to said condenser and vice versa, an expansion chamber for the refrigerant connected with said 0011- denser and permitting a free flow of refrig- 1 erant between said condenser and chamber at all times, means for conducting a supply of cooling water through said condenser, a tank.

arranged to hold' a body of brine in contact with said expansion chamber, and means for utilizing the flow of said cooling water to move said brine into and out of contact with said expansion chamber.

9. In an intermittent absorption refrigerating system, the combination of an absorber, a condenser, connections for conducting refrigerant from said absorber to said condenser and vice versa, an expansion chamber for the refrigerant connected with said con- 4 denser and permitting a free flow of refrigerant between said condenser and chamber at all t1mes,a container for holding a quantity of brine in contact with said expansion tact with said chamber.

10.v1n an intermittent absorption refrigerating system, the combination of an absorber, a condenser, connections enabling the refrigerant to flow freely at all times between said absorber and condenser. an expansion chamber into which the condensed refrigerant flows by gravity from said condenser during the condensing period, said condenser and chamber being constantly in free communication with each other, a brine container within which said expansion cham ber is located, and means for forcing air into said container to move the body of brine relatively to said chamber.

11. In an intermittent absorption refrigerating system, the combination of an absorber, a condenser, connections enabling the refrigerant to flow freely at all times between said absorber and condenser, an expansion chamber into which. the condensed refrigerant flows by gravity from said condenser during the condensing period, said condenser and chamber being constantly in free communication with each other, a brine container within which said expansion chamher is located, an air bell located in said brine container, and means for forcing air into said bell to move said body of brine to change its relationship to said chamber.

12. In an intermittent absorption refri crating system, the combination of an a sorber, a condenser, connections enabling the refrigerant to flow freely at all times between said absorber and condenser, an expansion chamber into which the condensed refrigerant flows by gravity from said condenser during the condensing period, said condenser and chamber being constantly in free communication with each other, a brine container within which said expansion chamber is located, an air bell located in said brine container, another air bell outside of said container, a pipe connection between said bells, a tank in which the latter bell is lo,- cated, and means-for conducting water to said tank whereby changes in the level of the water in the tank operate'to force air from the bell located therein into the bell in said container. i

13. That improvement in intermittent absorption refrigerating processes which consists in evaporating a refrigerant in a. suitable. container, absorbing said refrigerant in .a suitable medium, subsequently distillin off the refrigerant from said medium, con ensing the refrigerant so distilled, permitting the refrigerant to flow by gravity from said condenser into said container during the distilling period, and controlling the point at which the greater part of the refrigerant will be condensed by varying the relative rates of heat transfer of said condenser and container.

WILLL M GREEN.

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